fade

 int reading;

int btn_state;

int last_btn_state=LOW;

unsigned long last_debounce_time=0;

int brightness=0;

int fade_amount=5;

void setup() 

{

  Serial.begin(9600);

  pinMode(2,INPUT);

  pinMode(3,OUTPUT);

}

void loop() 

{

 reading=digitalRead(2);

 if(reading !=last_btn_state)

 {

  last_debounce_time=millis();

 }

 if((millis()-last_debounce_time)>50)

 {

  if(reading != btn_state)

  {

    btn_state=reading;

    if(btn_state==LOW)

    {

      chg_brightness();

    }

    else

    {

      if((millis()-last_debounce_time)>1000)

      {

        if(btn_state==LOW)chg_brightness();

      }

    }

  }

 }

 last_btn_state=reading;

}

void chg_brightness()

{

  brightness=brightness+fade_amount;

  if(brightness>255) brightness=255;

  if(brightness<0) brightness=0;

  if(brightness==0 || brightness==255) fade_amount=-fade_amount;

  analogWrite(3,brightness);

  Serial.println(brightness);

  delay(30);

}